The IAEA has recently published the Specific Safety Guide No. 30 (SSG-30)
on Safety Classification of Structures, Systems and Components in Nuclear Power Plants. SSG-30 provides a complete classification process to assist Member States in establishing a correct and comprehensive safety classification primarily for new builds. This Safety Guide could also be used to verify the correctness of the safety classification made according to earlier standards for existing plants. The recommended methodology emphasizes the usefulness of first identifying all SSCs needed to accomplish one safety function for the different plant states, and later assigning them to one safety category to make clearer the classification principle and to reinforce the overall consistency of the classification. Guidance is also provided to adjust the safety classification at the component level.
The Safety Classification of Structures, Systems and Components of Nuclear Power Plants was endorsed by the Commission on Safety Standards (CSS) in March 2013 and was published in June 2014.
This Safety Guide can be used by design firms when developing new reactors, by applicants to review the correctness and completeness of the classification proposed by the designers, or by the regulatory bodies to understand how the classification has been established, which facilitates their regulatory review.
In 2014 the IAEA Secretariat, with the support of the industry and operating organisations, began developing a Technical Document (TECDOC) to provide supplementary guidance to be applied to SSG-30. This TECDOC will provide supplementary engineering requirements for design and manufacturing which are expected to be associated with the different safety classes to achieve reliability and quality commensurate with their safety significance.